1.\" $NetBSD: byteorder.3,v 1.4 1996/10/13 04:08:34 christos Exp $ 2.\" 3.\" Copyright (c) 1983, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)byteorder.3 8.1 (Berkeley) 6/4/93 35.\" 36.Dd June 4, 1993 37.Dt BYTEORDER 3 38.Os BSD 4.2 39.Sh NAME 40.Nm htonl , 41.Nm htons , 42.Nm ntohl , 43.Nm ntohs 44.Nd convert values between host and network byte order 45.Sh SYNOPSIS 46.Fd #include <sys/types.h> 47.Ft in_addr_t 48.Fn htonl "in_addr_t host32" 49.Ft in_port_t 50.Fn htons "in_port_t host16" 51.Ft in_addr_t 52.Fn ntohl "in_addr_t net32" 53.Ft in_port_t 54.Fn ntohs "in_port_t net16" 55.Sh DESCRIPTION 56These routines convert 16 and 32 bit quantities between network 57byte order and host byte order. The types 58.Ft in_addr_t 59and 60.Ft in_port_t 61are defined by X/Open as: 62.Bd -literal -offset indent 63typedef u_int32_t in_addr_t; 64typedef u_int16_t in_port_t; 65.Ed 66.Pp 67On machines which have a byte order which is the same as the network 68order, routines are defined as null macros. 69.Pp 70These routines are most often used in conjunction with Internet 71addresses and ports as returned by 72.Xr gethostbyname 3 73and 74.Xr getservent 3 . 75.Sh SEE ALSO 76.Xr gethostbyname 3 , 77.Xr getservent 3 78.Sh HISTORY 79The 80.Nm byteorder 81functions appeared in 82.Bx 4.2 . 83.Sh BUGS 84On the 85.Tn VAX 86bytes are handled backwards from most everyone else in 87the world. This is not expected to be fixed in the near future. 88.Pp 89The `l' and `s' suffixes in the names are not meaningful in machines 90where long integers are not 32 bits. 91